This line is a metaphor for unity and connection. It represents how Shelley wants the elements of nature to blend together, just like how he wants to be united with his beloved.
"And the rivers with the ocean"
This continues the metaphor of unity, suggesting that everything in nature is interconnected and nothing is single. It’s a plea for the beloved to see that their union would be as natural as the flow of water from a river into the ocean.
"Nothing in the world is single"
This line asserts that everything in the world is connected, reinforcing the speaker’s argument for unity. It creates a sense of universality, implying that love and unity are inherent in the natural world.
"And the moonbeams kiss the sea"
This personification of moonbeams and the sea serves to strengthen the speaker’s argument. It suggests that if these inanimate elements of nature can interact in such a harmonious and loving way, so too should the speaker and his beloved.
"What is all this sweet work worth / If thou kiss not me?"
These lines express the speaker’s longing and desire. The speaker questions the value of all the beautiful connections in the world if he cannot be united with his beloved. It’s a poignant ending that underscores the speaker’s deep yearning for reciprocated love.
The poem is a kind of seductive argument, offering proof of a “divine law” that the world is full of interconnectedness—and that therefore the speaker and the person whom the speaker is addressing should become “connected” too.
